Rule of thumb

 作者:吉抓     |      日期:2019-03-08 03:02:00
By Kurt Kleiner IF YOU see someone making strange twitching movements with a gloved hand, don’t worry about their mental health. They are probably writing a blockbuster novel on their wearable computer. There are a number of computers designed for use on the move. But without a normal keyboard, getting data into these “wearables” is a problem. The answer could be a new one-handed sign language, according to its inventor at Stanford University in California. Vaughan Pratt, who leads the research on wearable computers at Stanford, has developed a sign language that he calls thumbcode. By touching your thumb against the tip, middle or base of each finger, and by grouping your fingers together in different ways, the language gives 96 different combinations, which represent upper and lowercase letters, numbers and other characters. Thumbcode is said to be device independent, meaning that the hand positions are the same whatever kind of device is reading them. Pratt is developing a glove which contains sensors that can detect each of the positions. This means you could write documents and e-mails as you walk down a street, for example. But the language could also be used with normal computers. Here there would be no need to use a glove, he says. A video camera and image recognition software could work out what characters your fingers are forming. “The training time is a lot less than for learning Morse code. Since it’s easy to learn the characters, that really overcomes the biggest obstacle. You can expect to get about 30 words per minute,” says Pratt. That compares favourably to the 60 words per minute most touch typists achieve. Once people learn to use a gloved system, they like it, says Bob Rosenberg, who studied gloved data input devices while at University College London. “People like the fact that they can type in a variety of positions,” he says. One-handed input devices based on typing date back to the creation of the computer mouse, when it was thought that people might type with one hand and control the mouse with the other. That didn’t happen, but several “chording keyboards”—on which characters are formed by pressing combinations of keys, just like musical chords—have been developed. However, these have caught on only in specialised wearable computing applications, such as underwater (see Technology, 30 October 1993, p 20) or military systems. Pratt says he is exploring other possibilities as well, including handwriting and voice recognition programs. But Pratt says both technologies are slow and prone to errors, and need a lot of improvement. IBM has already introduced a wearable computer that uses a voice recognition system. And 3Com’s PalmPilot, a popular handheld organiser,